I'm swapping a B16 into my 98 DX Hatch in about 2 weeks- Needed to know if anybody could answer a question/give an opinion so I could be ready with all my parts in time.

Will any aftermarket exhaust meant for a hatchback bolt right up to this setup?

Can anyone suggest an exhaust that's not very loud? I'm looking to stay pretty moderate with this car and just keep it a decent DD...

 

No, the exhuast's are different. The d16y7 (your hatch had this) has the cat and manifold built into one unit, the b16 does not.

You could run a si mid pipe and your stock axle back.
You could also always buy the exhuast for the hatch and head down to a exhuast shop and have them mod it to fit the b16.